Metal cable ties

[witsd]

Hey folks, just wondering if anyone has a quick idiot-proof description of where the line falls on what are acceptable methods to secure cables within escape routes.

Obviously plastic is not allowed due to melting when heated, but are metal staples good enough, or is there a specified minimum width / thickness / securing method?

Thanks in advance!

[bernicarey]

See this page, I think it includes the gen you require, even though its about their temporary use product:
https://tidi-cable.com/collections/18th ... 71-changes

[witsd]

Cheers Berni - so the short answer is that the wiring regs don't specify thicknesses etc.?

I've got a number of buildings that are choc-full of cabled pinned in place with tiny metal staples (that can be pulled loose with minimal effort. I'm struggling to believe that these are adequate, but I have to step carefully here - demanding that all of these are replaced will go down very badly unless I can back it up.

[Messy]

The 18th Edition of the Wiring Regulations, also known as BS 7671, came into full effect on 1st January 2019. This is the edition that included the following change;

521.10.02 - Wiring systems shall be supported so that they are not liable to premature collapse in the event of fire' Its weak in detail, but I hope that future amendments tighten this up with more detailed guidance before any other deaths occur

As Berni's link states, the origin of the change are two fatal fires where firefighters became entangled in dropped wiring and were unable to escape. In a former life, I was a firefighter and we trained for this eventuality as it wasn't uncommon. But perhaps with the rise in entryphone, cctv and other security and safety systems, perhaps there's more cabling in common parts of flats. Firefighters now carry knives like divers do, to help assist in entanglement. Not an easy task with zero visibility, extreme heat and the clock running on how much air you have left!


I assume you are conducting a fire risk assessment. If so, it is common practice (and good practice) to refer to quality standards (like British standards) when considering control measures. But you do not have to. Your decisions should be based on the risk presented and not an exercise in applying strict adherence to a British standard or other COP.

So if you find cabling in plastic self adhesive trunking in the common parts of a block of flats installed before January 2019 - you may wish to apply common sense and advise its removed from high risk areas ( not everywhere) like common parts in order to reduce the risk. You may want to add a note to say the 2018 edition cannot be retrospectively applied, but the FRA is not an audit of compliance with British standards, it is an assessment of risk .

You may have seen the Grenfell Inquiry cross examination of fire crews. Put yourself in an Inquest being questioned like that. I have been there in Coroers and Crowns Court and its hideously stressful.

"So Witsd, you were aware that it was dangerous to have plastic cable fittings in an escape route in that it may drop in a fire and entangle those escaping, and furthermore I put it to you that you were fully aware of BS7671 as we have evidence from a website chat room - 'HSFB' -where you engaged in a conversation about the subject of 7671. But despite your knowledge, you ignored any opportunity to make the premises safe and prevent the death of my clients and their children just because the plastic fittings were installed before January 2019". It that right Mr Witsd?....... Trust me, its not a nice place to be!

The big issue is, as the changes to the wiring regs have been bought about by concerns for firefighter safety, its difficult to use that rationale in a FRA under the RRO (in England and Wales). Under this legislation, the assessment only considers the risk to 'relevant persons'. The definition of that phrase does NOT extend to operational firefighters engaged in firefighting at an address.

So be careful and record that your recommendations to improve wiring for the safety of relevant persons, primarily residents, guest and anyone working in the building


As far as removing all wiring that does not meet the current BS 7671, that would be tough to justify - so cherry pick the higher risk areas like those that are main means of escape or are in high fire risk areas like kitchens and plant rooms (including corridors outside)

[witsd]

Sorry, I should have been a little clearer.

This is not actually part of an FRA precisely. Rather, we have taken over for the SFRS, who usually conduct quarterly inspections of MSFs. We've slapped a pretty heavy disclaimer on the front of it pointing out that it is not anything close to exhaustive.

There's also the factor that we know full well that unless the issue os going to kill people right now, there's no way it can currently be repaired - the majority of repairs staff are furloughed, shielding etc.

Having said that, I have been recording and recommending the removal / securing of all loose wiring and that held by plastic clips. What I don't know whether to make a fuss about is the wiring that has been stapled into the walls / ceilings. How long will that remain in situ when heated?

Also, I'm in Scotland, so we only have irrelevant persons! More seriously, I'm pretty certain that an entangled fire fighter wouldn't be much help towards the people that southerners legally have to care about, so surely it's all one and the same?!